Physics Letters B最新文献

{"title":"Signature of 0+ excited state and shape coexistence in 94Kr through 93Kr(d,p)94Kr reaction","authors":"D. Walter ,&nbsp;R. Kanungo ,&nbsp;M. Holl ,&nbsp;S. Roy-Garand ,&nbsp;B.S. Hu ,&nbsp;J.D. Holt ,&nbsp;M. Alcorta ,&nbsp;C. Andreoiu ,&nbsp;S. Bhattacharjee ,&nbsp;A.A. Chen ,&nbsp;A. Chester ,&nbsp;D. Connolly ,&nbsp;B. Davids ,&nbsp;N. Esker ,&nbsp;F. Garcia ,&nbsp;S. Gillespie ,&nbsp;G. Hackman ,&nbsp;S. Ishimoto ,&nbsp;R. Krücken ,&nbsp;P. Jassal ,&nbsp;C. Waterfield","doi":"10.1016/j.physletb.2025.139352","DOIUrl":"10.1016/j.physletb.2025.139352","url":null,"abstract":"<div><div>A measurement of the excitation spectrum of ⁹⁴Kr via one-neutron transfer to the ground state of ⁹³Kr using the ⁹³Kr(<em>d,p</em>)⁹⁴Kr reaction at 8<em>A</em> MeV, observing the outgoing protons, performed with the IRIS facility at TRIUMF is reported. Two states in ⁹⁴Kr, at 1.50±0.14 MeV and 2.20±0.14 MeV, were observed. An adiabatic-wave approximation analysis of the differential cross sections leads us to identify the lower energy state as being populated with neutron transfer to the 3<span><math><msub><mrow><mi>s</mi></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msub></math></span> orbital. This leads to the first observation of the lowest 0⁺ excited state in ⁹⁴Kr, hence signaling shape co-existence. Theoretical calculations performed within the in-medium similarity renormalization group framework are presented that also show the existence of a low-energy 0⁺ state, aligning qualitatively with the observation.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139352"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cosmological implications of f(R,Σ,T) gravity: A unified approach using OHD and SN ia data","authors":"N. Myrzakulov ,&nbsp;S.H. Shekh ,&nbsp;Anirudh Pradhan","doi":"10.1016/j.physletb.2025.139369","DOIUrl":"10.1016/j.physletb.2025.139369","url":null,"abstract":"<div><div>This paper investigates the cosmological implications of the modified gravity framework known as <span><math><mi>f</mi><mo>(</mo><mi>R</mi><mo>,</mo><mi>Σ</mi><mo>,</mo><mi>T</mi><mo>)</mo></math></span> gravity, focusing on its potential to unify and extend current cosmological models. The theory, introduced by Bakry and Ibraheem in 2023, combines the Ricci scalar, a scalar parameter representing torsion or other geometric properties, and the trace of the energy-momentum tensor. By analyzing observational Hubble data (OHD) and the Pantheon compilation of Type Ia Supernovae (SN Ia), we explore how this framework provides the accelerated expansion of the universe, the nature of dark energy, and phenomena like the Big Rip singularity. Employing the Friedmann-Robertson-Walker (FRW) metric and solving the modified field equations, we derive key cosmological parameters such as the Hubble constant and matter energy density parameter. These parameters are constrained through statistical analysis of observational data, yielding and from OHD, and from SN Ia. The evolution of the equation of state (EoS) parameter, isotropic pressure, and energy density is also investigated. By considering energy conditions and stability criteria, the study highlights the viability of gravity as an alternative framework to General Relativity and models. Our findings affirm the model's compatibility with current observational evidence and its potential to the universe's past and future dynamics.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139369"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143547971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurement of spin-density matrix elements in Δ++(1232) photoproduction","authors":"","doi":"10.1016/j.physletb.2025.139368","DOIUrl":"10.1016/j.physletb.2025.139368","url":null,"abstract":"<div><div>We measure the spin-density matrix elements (SDMEs) of the <span><math><msup><mrow><mi>Δ</mi></mrow><mrow><mo>+</mo><mo>+</mo></mrow></msup><mo>(</mo><mn>1232</mn><mo>)</mo></math></span> in the photoproduction reaction <span><math><mi>γ</mi><mi>p</mi><mo>→</mo><msup><mrow><mi>π</mi></mrow><mrow><mo>−</mo></mrow></msup><msup><mrow><mi>Δ</mi></mrow><mrow><mo>+</mo><mo>+</mo></mrow></msup><mo>(</mo><mn>1232</mn><mo>)</mo></math></span> with the GlueX experiment in Hall D at Jefferson Lab. The measurement uses a linearly–polarized photon beam with energies from 8.2 to 8.8 GeV and the statistical precision of the SDMEs exceeds the previous measurement by three orders of magnitude for the momentum transfer squared region below 1.4 GeV². The data are sensitive to the previously undetermined relative sign between couplings in existing Regge-exchange models. Linear combinations of the extracted SDMEs allow for a decomposition into natural and unnatural–exchange amplitudes. We find that the unnatural exchange plays an important role in the low momentum transfer region.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"863 ","pages":"Article 139368"},"PeriodicalIF":4.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143548253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Universal laws for nuclear contacts","authors":"Tongqi Liang ,&nbsp;Dong Bai ,&nbsp;Zhongzhou Ren","doi":"10.1016/j.physletb.2025.139351","DOIUrl":"10.1016/j.physletb.2025.139351","url":null,"abstract":"<div><div>The nuclear contact characterizes the nucleon-nucleon pairs in close proximity and serves as an important tool for studying the short-range correlations (SRCs) within atomic nuclei. While they have been extracted for selected nuclei, the investigation of their behavior across the nuclear chart remains limited. Very recently, Yankovich, Pazy, and Barnea have proposed a set of universal laws (YPB laws) to describe the correlation between nuclear contacts and nuclear radii and tested their laws for a small number of nuclei by using the Woods-Saxon mean-field model Yankovich et al. (2021) <span><span>[32]</span></span>. In this Letter, we extend their study to a majority part of the nuclear chart within the framework of the Skyrme Hartree-Fock-Bogolyubov model, which incorporates several essential beyond-mean-field features and offers a more accurate description of the bulk properties of atomic nuclei. Our results suggest that the YPB laws hold as a good approximation for different nuclear mass regions, with minor deviations attributed to, e.g., isospin-breaking effects. Our work lays a firm foundation for future applications of the YPB laws in finite nuclei and provides new evidence for the long-range nature of the relative abundance of short-range pairs.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"863 ","pages":"Article 139351"},"PeriodicalIF":4.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurement of the neutron total cross section of Iron at the Back-n white neutron source of CSNS","authors":"Jiangbo Bai ,&nbsp;Jingyu Tang ,&nbsp;Liqun Shi ,&nbsp;Yonghao Chen ,&nbsp;Han Yi ,&nbsp;Guohui Zhang ,&nbsp;Haofan Bai ,&nbsp;Jie Bao ,&nbsp;Ping Cao ,&nbsp;Zhen Chen ,&nbsp;Zengqi Cui ,&nbsp;Anchuan Fan ,&nbsp;Ruirui Fan ,&nbsp;Changqing Feng ,&nbsp;Fanzhen Feng ,&nbsp;Keqing Gao ,&nbsp;MinHao Gu ,&nbsp;Changcai Han ,&nbsp;Guozhu He ,&nbsp;Yongcheng He ,&nbsp;Kejun Zhu","doi":"10.1016/j.physletb.2025.139355","DOIUrl":"10.1016/j.physletb.2025.139355","url":null,"abstract":"<div><div>The neutron total cross section of iron (^natFe) plays an important role in the basic science of nuclear physics, nuclear technology and nuclear energy application. A new measurement of the total cross section of iron from 0.3 eV to 150 MeV was carried out in single and double bunch modes by transmission method and time of flight method with multi-cell fast fission ionization chamber (FIC) with ²³⁵U and ²³⁸U coating materials at the China Spallation Neutron Source (CSNS). Normalized fission counts-neutron energy spectra for sample-in and sample-out states were obtained and superimposed. The Bayesian method was used to eliminate the influence of the double-bunch problem on neutron measurement in the energy region above 10 keV. The transmissions obtained in single bunch and unfolded in double bunch coincided well. From 0.3 eV to 150 MeV, the ratio of most energy points of cross section in single bunch and in double bunch fluctuates within 10 %. In the energy range of 0.3 eV to 10 keV, the experimental results using 20 mm and 40 mm thickness iron samples both agree very well with the evaluated data of JEFF-3.3 and ENDF/B-VIII.0 at most energy points, fluctuating within 3 %. In the energy range of 10 keV to 150 MeV, the results agree well with the evaluated data in terms of values and trends. The main resonance peaks of the total cross section of iron at the energies of 3.94 keV, 6.24 keV, 7.76 keV, 27.9 keV, 52.1 keV, 74.1 keV, 83.9 keV, 141 keV, 170 keV, 188 keV and 386 keV are well represented in our results. The relative uncertainties of the total cross sections using the 40 mm iron sample by FIC-²³⁵U are within 2 % at most energy points. In 1.5 MeV-140 MeV region, the relative uncertainties of the total cross section using the 20 mm iron and 40 mm iron samples by FIC-²³⁸U are around 2 % and 1 %, respectively. The total cross section results can be used as a reference for nuclear data evaluation.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"863 ","pages":"Article 139355"},"PeriodicalIF":4.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First detection of a tagged neutrino in the NA62 experiment","authors":"","doi":"10.1016/j.physletb.2025.139345","DOIUrl":"10.1016/j.physletb.2025.139345","url":null,"abstract":"<div><div>The NA62 experiment at the CERN SPS reports the first detection of a tagged neutrino candidate based on the data collected in 2022. The candidate consists of a <span><math><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup><mo>→</mo><msup><mrow><mi>μ</mi></mrow><mrow><mo>+</mo></mrow></msup><msub><mrow><mi>ν</mi></mrow><mrow><mi>μ</mi></mrow></msub></math></span> decay where the charged particles are reconstructed and the neutrino is detected through a charged-current interaction in a liquid krypton calorimeter.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"863 ","pages":"Article 139345"},"PeriodicalIF":4.3,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143548252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fractional-charge hadrons and leptons to tell the Standard Model group apart","authors":"R. Alonso,&nbsp;D. Dimakou,&nbsp;M. West","doi":"10.1016/j.physletb.2025.139354","DOIUrl":"10.1016/j.physletb.2025.139354","url":null,"abstract":"<div><div>The gauge group of strong and electroweak interactions in Nature could be any of the four that share the same Lie algebra, <span><math><mi>S</mi><mi>U</mi><msub><mrow><mo>(</mo><mn>3</mn><mo>)</mo></mrow><mrow><mi>c</mi></mrow></msub><mo>×</mo><mi>S</mi><mi>U</mi><msub><mrow><mo>(</mo><mn>2</mn><mo>)</mo></mrow><mrow><mi>L</mi></mrow></msub><mo>×</mo><mi>U</mi><msub><mrow><mo>(</mo><mn>1</mn><mo>)</mo></mrow><mrow><mi>Y</mi></mrow></msub><mo>/</mo><msub><mrow><mi>Z</mi></mrow><mrow><mi>p</mi></mrow></msub><mo>≡</mo><msub><mrow><mi>G</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span> with <span><math><msub><mrow><mi>Z</mi></mrow><mrow><mi>p</mi></mrow></msub><mo>=</mo><mrow><mo>{</mo><msub><mrow><mi>Z</mi></mrow><mrow><mn>6</mn></mrow></msub><mo>,</mo><msub><mrow><mi>Z</mi></mrow><mrow><mn>3</mn></mrow></msub><mo>,</mo><msub><mrow><mi>Z</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>,</mo><msub><mrow><mi>Z</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>}</mo></mrow></math></span>. Each of these cases allows in its spectrum for the matter fields of the SM but also for new distinctive representations, e.g. under the assumption that <span><math><msub><mrow><mi>q</mi></mrow><mrow><mi>L</mi></mrow></msub></math></span> possesses the minimum possible hypercharge in Nature, <span><math><msub><mrow><mi>G</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span> allows for particles with a multiple of <span><math><mi>p</mi><mspace></mspace><mi>e</mi><mo>/</mo><mn>6</mn></math></span> for electric charge. This letter discusses how these new possibilities in the spectrum could be used to tell the SM group apart.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"863 ","pages":"Article 139354"},"PeriodicalIF":4.3,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Helicity correlation of neighboring dihadron","authors":"Fei Huang ,&nbsp;Tianbo Liu ,&nbsp;Yu-Kun Song ,&nbsp;Shu-Yi Wei","doi":"10.1016/j.physletb.2025.139346","DOIUrl":"10.1016/j.physletb.2025.139346","url":null,"abstract":"<div><div>The spin correlation of final-state hadrons provides a novel platform to explore the hadronization mechanism of polarized partons in unpolarized high-energy collisions. In this work, we investigate the helicity correlation of two hadrons originating from the same single parton. The production of such a dihadron system is formally described by the dihadron fragmentation function, in which the helicity correlation between the two hadrons arise from both the long-distance nonperturbative physics and the perturbative QCD evolution. Beyond the extraction of the dihadron fragmentation function, we demonstrate that it is also a sensitive observable to the longitudinal spin transfer, characterized by the single hadron fragmentation function <span><math><msub><mrow><mi>G</mi></mrow><mrow><mn>1</mn><mi>L</mi></mrow></msub></math></span>. This intriguing connection opens up new opportunities for understanding the spin dynamics of hadronization and provides a complementary approach to corresponding studies using polarized beams and targets.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139346"},"PeriodicalIF":4.3,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Equivalence of 1-loop RG flows in 4d Chern-Simons and integrable 2d sigma-models","authors":"Nat Levine","doi":"10.1016/j.physletb.2025.139325","DOIUrl":"10.1016/j.physletb.2025.139325","url":null,"abstract":"<div><div>We argue for the matching of 1-loop divergences between 4d Chern-Simons theory with Disorder defects and the corresponding integrable 2d <em>σ</em>-models of non-ultralocal type. Starting from the 4d path integral, we show under general assumptions that the 1-loop divergences localise to the 2d defects. They match the ‘universal’ formulae developed in [<span><span>arXiv:2209.05502</span><svg><path></path></svg></span>] for the 1-loop RG flows of integrable 2d <em>σ</em>-models. Our argument uses an alternate path integral representation for the 1-loop effective action and the known classical equivalence between the 4d and 2d theories.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139325"},"PeriodicalIF":4.3,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prospects for measuring neutrino mass with 21-cm forest","authors":"Yue Shao ,&nbsp;Guo-Hong Du ,&nbsp;Tian-Nuo Li ,&nbsp;Xin Zhang","doi":"10.1016/j.physletb.2025.139342","DOIUrl":"10.1016/j.physletb.2025.139342","url":null,"abstract":"<div><div>Both particle physics experiments and cosmological observations have been used to explore neutrino properties. Cosmological researches of neutrinos often rely on the early-universe cosmic microwave background observations or other late-universe probes, which mostly focus on large-scale structures. We introduce a distinct probe, the 21-cm forest, that differs from other probes in both time and scale. Actually, the 21-cm forest is a unique tool for studying small-scale structures in the early universe. Below the free-streaming scale, massive neutrinos suppress the matter power spectrum, influencing small-scale fluctuations in the distribution of matter. The one-dimensional (1D) power spectrum of the 21-cm forest can track these fluctuations across different scales, similar to the matter power spectrum, providing an effective method to constrain neutrino mass. Although heating effects in the early universe can also impact the 1D power spectrum of the 21-cm forest, we assess the potential of the 21-cm forest as a tool for measuring neutrino mass, given that the temperature of the intergalactic medium can be constrained using other methods within a certain range. In the ideal scenario, the 21-cm forest observation will have the ability to constrain the total neutrino mass to around 0.1 eV. With the accumulation of observational data and advancements in observational technology, the 21-cm forest holds great promise as an emerging and potent tool for measuring neutrino mass.</div></div>","PeriodicalId":20162,"journal":{"name":"Physics Letters B","volume":"862 ","pages":"Article 139342"},"PeriodicalIF":4.3,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}